Thermoform packaging machine

ABSTRACT

A thermoform packaging machine comprising a forming station for producing troughs in a bottom film, a sealing station for sealing troughs that contain a product, and at least one cutting station arranged on a machine frame. The thermoform packaging machine may include at least two clamp chains for holding and conveying the bottom film in a production direction through the packaging machine. The clamp chains may be guided by chain guides that extend at least from the forming station along an infeed line to the sealing station. Each chain guide may include an upper guide surface and a lower guide surface between which a respective one of the clamp chains is guided. In one embodiment, the chain guides are oriented horizontally at and along both the forming station and the sealing station and the chain guide ascends from the forming station to the sealing station along the infeed line.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to German Patent Application Number 202016000757.3 filed Feb. 3, 2016, to Elmar Ehrmann, currently pending, and European Patent Application Number 16167437.9 filed Apr. 28, 2016, to Elmar Ehrmann, currently pending, the entire disclosures of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a thermoform packaging machine having clamping chains and chain guides for guiding a bottom film through the packaging machine, wherein troughs formed in the bottom film are filled with products fed by a product infeed belt.

BACKGROUND OF THE INVENTION

DE 102 24 237 A1 discloses a thermoform packaging machine for producing packages with a sealed seam that is inclined relative to the horizontal. A stack of products of several slices of a foodstuff is fed into a trough formed in a bottom film web by an obliquely arranged conveyor belt configured as a retractable belt. One reason for the inclination of the conveyor belt relative to the thermoform packaging machine and the film conveying plane, respectively, is to be seen in the arrangement of the forming station being above the film conveying plane. The conveyor belt must be arranged above the uppermost obstructing contour on the forming station and, due to the fact that the conveyor belt extends at an oblique angle down to the film conveying plane, an area that extends from the forming station up to the beginning of the infeed line is defined and this area is not utilized by any work station in the existing packaging machine.

SUMMARY OF THE INVENTION

It is the object of the present invention to reduce the machine length of a thermoform packaging machine. This object is achieved by a thermoform packaging machine according to teachings of the present disclosure.

The thermoform packaging machine according to the present invention may comprise at least two clamp chains for holding a bottom film, wherein each clamp chain is disposed on and holds a side of the bottom film and for conveying the bottom film along a production direction of the thermoform packaging machine. The clamp chains may be guided in chain guides. The chain guides may each comprise an upper guide surface and a lower guide surface between which a respective one of the clamp chains is guidable. The thermoform packaging machine may comprise a forming station for producing troughs in a bottom film, a sealing station and at least one cutting station, all of which are arranged in this sequence in the production direction and arranged on a machine frame. The thermoform packaging machine according to the present invention may include the chain guides extending at least from the forming station to the sealing station along an infeed line and the upper guide surface may be oriented horizontally at and along the forming station and the upper guide may have a first vertical distance from an installation surface of the machine frame of the thermoform packaging machine.

The chain guides may be oriented horizontally at and along the sealing station and the upper guide surface may have a second vertical distance from the installation surface, wherein in one embodiment, the second distance may be larger than the first distance by at least 100 mm. The chain guide may be disposed, at least sectionwise, in an ascending orientation along the infeed line. This structural design of a thermoform packaging machine allows a short infeed line, since a product infeed belt can easily feed products horizontally and place them directly into the troughs formed in the bottom film. The inclined position of the troughs at the infeed line may be particularly advantageous for some shapes of troughs and products.

Preferably, the chain guide is inclined at an angle of 10° to 30° relative to the horizontal along the infeed line.

The chain guide is configured such that, preferably, it is continuous to a very large extent from the forming station along the infeed line up to the sealing station, so as to avoid transitions between chain guide sections, as transitions may lead to rough running of the chain.

According to one embodiment, the forming station may be configured to form troughs in the bottom film with a trough depth of at least 100 mm in the bottom film.

The forming station may include a male die part for supporting the forming process, so as to support the thermoforming of the bottom film in female die parts in the forming tool lower part using pressurized air from above and/or vacuum from below the bottom film. This embodiment may allow for the performance and the forming quality to be increased.

A packaging assembly according to the present invention comprises the presently described thermoform packaging machine and a product infeed belt. The packaging assembly may include the product infeed belt having an inclination at an angle of less than five degrees (5°) relative to the horizontal. Preferably, the angle of the product infeed belt is zero degrees (0°).

According to one embodiment, the product infeed belt may be a retractable belt, so as to feed the product partially directly into the trough itself and thus place the product very accurately at its infeed position.

Preferably, in one embodiment, the product infeed belt may have a vertical dimension of less than 50 mm in the area above the forming station and in the area of a front edge of the product infeed belt, so that less space is required when the product infeed belt enters the trough in the bottom film. A vertical dimension that narrows towards an end of the product infeed belt is also within the scope of the present invention.

Preferably, in one embodiment, the product infeed belt may be provided above the forming station and may extend up to the infeed line and partially along the infeed line. In this embodiment, products that are produced upstream of the thermoform packaging machine may be conveyed along or past the forming station up to an infeed site in a structurally very simple manner.

According to one embodiment, an advance movement of the product infeed belt may be synchronized with an advance movement of the clamp chains, and thus of the troughs, such that a product can be fed into the trough while the trough is being advanced in an advance movement by the clamp chains. In this way, the placement of the product in the trough may also be carried out precisely.

Other aspects and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments and the accompanying drawing figures.

DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

In the following, an advantageous embodiment of the present invention will be explained in more detail making reference to a drawing, in which:

FIG. 1 is a schematic side view of one embodiment of a packaging assembly comprising a thermoform packaging machine and a product infeed belt in accordance with the teachings of the present disclosure;

FIG. 2 is a schematic side view of one embodiment of the infeed line of a thermoforming packaging machine in relation to a product infeed belt in a first phase in accordance with the teachings of the present disclosure;

FIG. 3 is a schematic detail view of one embodiment of the infeed line of a thermoforming packaging machine in relation to a product infeed belt in a second phase in accordance with the teachings of the present disclosure;

FIG. 4 is a schematic detail view of another embodiment of the infeed line of a thermoforming packaging machine in relation to a product infeed belt in a first phase in accordance with the teachings of the present disclosure; and

FIG. 5 is a schematic detail view of another embodiment of the infeed line of a thermoforming packaging machine in relation to a product infeed belt in a second phase in accordance with the teachings of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. For purposes of clarity in illustrating the characteristics of the present invention, proportional relationships of the elements have not necessarily been maintained in the drawing figures.

The following detailed description of the invention references specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the present invention. The present invention is defined by the appended claims and the description is, therefore, not to be taken in a limiting sense and shall not limit the scope of equivalents to which such claims are entitled.

FIG. 1 shows a schematic side view of a packaging assembly 1 comprising an intermittently operating thermoform packaging machine 2 according to the present invention and a product infeed belt 3. Thermoform packaging machine 2 comprises a machine frame 4 oriented along a production direction R and installed upon an installation surface A on the lower side of the machine frame 4. At the beginning of the thermoform packaging machine 2 (the beginning being on the right-hand side in FIG. 1) an unwinding device 5 for a bottom film/foil 6 is provided. The bottom film 6 is supplied to a forming station 8 by two clamp chains 7 that are arranged such that one clamp clamps each side of the bottom film 6, so that forming station 8 thermoforms troughs 11 with a vertical trough depth T in the bottom film 6. In addition, downstream of the forming station 8 in the production direction R, the present thermoforming packaging machine 2 includes an oblique infeed line 9 that is inclined at an angle θ relative to a horizontal and that is used and allows for feeding a product 10 into thermoformed troughs 11 (see also FIGS. 2-5). In a further production sequence in the production direction, the forming station 8 and oblique infeed line 9 are followed by a sealing station 12 for closing the troughs 11 that have been filled with a product 10 with a cover film 13, and a first cutting station 14 configured as a cross cutting station. A second cutting unit 15 that is a longitudinal cutting station may be arranged downstream of the first cross cutting station 14 to separate the sealed packages 16. A conveyor belt 17 may be downstream of the first and/or second cutting unit to convey the separated packages 16 out of the thermoform packaging machine 2. The thermoform packaging machine 2 comprises a control unit 18 configured for controlling not only the drive 19 a (in one embodiment, a servomotor for driving clamp chains 7), but also the drive 19 b of the product infeed belt 3, so that the speeds of the two drives 19 a and 19 b can be synchronized with one another or adapted to one another for allowing an optimum execution of the infeed process in accordance with the product 10 and/or the trough 11,

The clamp chains 7 are guided in a chain guide 30 as schematically shown in FIG. 1 as dot-and-dash lines extending above and below the broken line for the clamp chains 7 and in parallel therewith. Such a chain guide 30 is known, for example, from DE 102006005405 A1. The chain guides 30 have an upper guide surface O and a lower guide surface U, between which a clamp chain 7 is guided. The upper guide surface O along the forming station 8 is oriented horizontally and has a first vertical distance V1 from an installation surface A. The upper guide surface O along the sealing station 12 is oriented horizontally and has a second vertical distance V2 from the installation surface A.

FIG. 2 shows a schematic side view of the routing of the clamp chains 7 and thus of the bottom film 6 from the forming station 8 to the sealing station 12. In the forming station 8, one or a plurality of troughs 11, which are arranged in succession and/or side-by-side and which define a format, are formed in the bottom film 6. The bottom film 6 may, for example, be configured as any applicable flexible film or foil having a film thickness between 100 μm and 300 μm. The clamp chains 7 are moved synchronously per work cycle by a film feed length V in the production direction R so as to provide respective new troughs to be filled for the infeed line 9 and the product infeed belt 3. FIG. 2 additionally shows a schematic detail view of the infeed line 9 with the product infeed belt 3 in the first phase, in the case of which the product infeed belt 3 is configured as a retractable belt and the front edge 20 itself is extendable and retractable in the orientation of the product infeed belt 3. Such retractable belts are known, for example from DE 2516583 A1. FIG. 2 shows in this first phase the product infeed belt 3 in its extended position, at which the front edge 20 enters the trough 11, which has been suitably positioned, and is then retracted, as shown in FIG. 3. The product infeed belt 3 has a vertical height H in the area above the forming station 8.

In FIG. 3, the product infeed belt 3 is moved such that the upper part 3 a of the product infeed belt 3 stands still (and is stationary), whereas the lower part 3 b is retracted to the right in a direction opposite to the production direction R synchronously with the front edge 20 and a deflection pulley 21, respectively. In one embodiment, a deflection edge may be used instead of the deflection pulley 21. Through this operation, the product 10 may thus reliably and precisely placed into the trough 11.

FIGS. 4 and 5 show an alternative embodiment of the product infeed belt 3. The product infeed belt 3 does not have a movable front edge 20. During the infeed process, the movement of the product infeed belt 3 and the advance movement V of the clamp chains 7 are adapted to one another using of the control unit 18 such that the product 10 will be moved into the trough 11 that moves at an oblique angle past the front edge 20. In order to detect the position of the product 10 on the product infeed belt 3, a sensor 22 (see FIG. 5) in the form of a light barrier may be arranged at the left end of the product infeed belt 3, so that the control unit 18 will be able to control, in accordance with the position of the product 10 on the product infeed belt 3, the start as well as the speeds of the respective drives 19 a and 19 b for the infeed process.

From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure. It will be understood that certain features and sub combinations are of utility and may be employed without reference to other features and sub combinations. This is contemplated by and is within the scope of the claims. Since many possible embodiments of the invention may be made without departing from the scope thereof, it is also to be understood that all matters herein set forth or shown in the accompanying drawings are to be interpreted as illustrative and not limiting.

The constructions and methods described above and illustrated in the drawings are presented by way of example only and are not intended to limit the concepts and principles of the present invention. Thus, there has been shown and described several embodiments of a novel invention. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. The terms “having” and “including” and similar terms as used in the foregoing specification are used in the sense of “optional” or “may include” and not as “required”. Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow. 

What is claimed is:
 1. A thermoform packaging machine comprising: at least two clamp chains for holding a bottom film and for conveying the bottom film in a production direction of the thermoform packaging machine, wherein each of the clamp chains are guided in a chain guide; a forming station for producing troughs in the bottom film, a sealing station and at least one cutting station, which are arranged on a machine frame in this sequence in the production direction, wherein the chain guides extend at least from the forming station along an infeed line to the sealing station, wherein the chain guides each comprise an upper guide surface and a lower guide surface between which a respective one of the at least two clamp chains is guided; and the upper guide surface is oriented horizontally at and along the forming station and has a first vertical distance from an installation surface along the forming station, wherein the chain guides are oriented horizontally at and along the sealing station and the upper guide surface has a second vertical distance from the installation surface along the sealing station; and wherein the second distance is larger than the first distance by at least 100 mm, and wherein the chain guides have an ascending orientation along the infeed line.
 2. The thermoform packaging machine according to claim 1, wherein the chain guides are inclined at an angle (β) of 10° to 30° relative to the horizontal along the infeed line.
 3. The thermoform packaging machine according to claim 1, wherein the chain guides are substantially continuous from the forming station along the infeed line to the sealing station.
 4. The thermoform packaging machine according to claim 1, wherein the forming station is configured to form troughs in the bottom film having a trough depth of at least 100 mm.
 5. The thermoform packaging machine according to claim 1, wherein the forming station comprises a male die part used in the trough forming process.
 6. A packaging assembly comprising a thermoform packaging machine of claim 1 and a product infeed belt, wherein the product infeed belt has an inclination at an angle of less than five degrees (5°) relative to the horizontal.
 7. The packaging assembly according to claim 6, wherein the product infeed belt includes a retractable belt.
 8. The packaging assembly according to claim 6, wherein the product infeed belt has a vertical dimension of less than 50 mm.
 9. The packaging assembly according to claim 6, wherein the product infeed belt is provided above the forming station and extends to the infeed line and partially along the infeed line.
 10. The packaging assembly according to claim 6, wherein a first advance movement of the product infeed belt is synchronized with a second advance movement of the clamp chains such that a product can be fed into the trough of the bottom film while the trough is being advanced in the second advance movement. 